A variety of flavorants have been developed and proposed for incorporation into tobacco products. Illustrative of such tobacco flavorants are those described in U.S. Pat. Nos. 3,580,259; 3,625,224; 3,722,516; 3,750,674; 3,879,425; 3,881,025; 3,884,247; 3,890,981; 3,903,900; 3,914,451; 3,915,175; 3,920,027; 3,924,644; 3,937,228; 3,943,943; 3,568,387; 3,379,754; and the like.
The high degree of volatility and ease of sublimation of flavorant additives in tobacco products have presented problems in the manufacturing operations, and have resulted in a decreased shelf-life of the products due to losses of flavorant by evaporation on storage.
Recent developments have involved incorporating a low volatility organic additive to a smoking composition, which under smoking conditions is pyrolyzed into one or more fragments that function to improve the taste and character of mainstream tobacco smoke, and in some cases a consequential improvement of sidestream smoke aroma.
U.S. Pat. No. 3,312,226 describes smoking tobacco compositions which contain an ester additive such as l-menthyl linalool carbonate. Under smoking conditions pyrolysis of the carbonate ester releases menthol which flavors the mainstream smoke.
U.S. Pat. No. 3,332,428 and U.S. Pat. No. 3,419,543 describe smoking tobacco compositions which contain a menthyl carbonate ester of a glycol or saccharide, which under smoking conditions decomposes to release free menthol into the mainstream smoke. U.S. Pat. No. 3,499,452 discloses similar smoking tobacco compositions in which a carbonate ester additive releases flavorant volatiles other than menthol.
Another method being practiced for preventing premature volatilization of a smoking composition flavorant additive is by the utilization of microcapsules which encapsulate a flavorant that is being incorporated in the combustible filler. One disadvantage of this technique is the tendency for the microcapsules to separate from the filler and produce products with variable quantities of flavorant.
U.S. Pat. No. 4,889,144 describes a method wherein microcapsules containing encapsulated flavorant are introduced into the filter portion of a cigarette rather than the combustible filler. The release of the flavorant is achieved by applying pressure to the filter to rupture the microcapsules and release the encapsulated flavorant.
There is continuing research effort to develop novel flavorant-release additives, and low delivery smoking compositions which generate mainstream smoke with enhanced taste and sidestream smoke with a pleasant aroma under smoking conditions.
Accordingly, it is an object of this invention to provide smoking compositions having incorporated therein a flavorant-release component which is characterized by lack of mobility and/or volatility under product storage conditions.
It is another object of this invention to provide a flavorant-release additive in the form of a filament for incorporation in the combustible filler of cigarette products.
It is a further object of this invention to provide a process for the production of a flavorant-release additive for cigarette products which is in the form of a filament that releases encapsulated flavorant under normal cigarette smoking conditions.
Other objects and advantages of the present invention shall become apparent from the following description and example.